Abstract: High-resolution magnetic resonance imaging (MRI) provides non-invasive images of retinal anatomy, physiology, and function with depth-resolved laminar resolution. Eye movement and drift, however, could limit high spatial resolution imaging, and anesthetics that minimize eye movement could significantly attenuate retinal function. The aim of this study was to determine the optimal anesthetic preparations to minimize eye movement and maximize visual-evoked retinal response in rats. Eye movements were examined by imaging of the cornea with a charge-coupled device (CCD) camera under isoflurane, urethane, ketamine/xylazine, and propofol anesthesia at typical dosages in rats. Combination of the paralytic pancuronium bromide with isoflurane or ketamine/xylazine anesthesia was also examined for the eye movement studies. Visual-evoked retinal responses were evaluated using full-field electroretinography (ERG) under isoflurane, ketamine/xylazine, urethane, and ketamine/xylazine + pancuronium anesthesia in rats. The degree of eye movement, measured as displacement per unit time, was the smallest under 1% isoflurane + pancuronium anesthesia. The ketamine/xylazine groups showed larger dark-adapted ERG a- and b-waves than other anesthetics tested. The isoflurane group showed the shortest b-wave implicit times. Photopic ERGs in the ketamine/xylazine groups showed the largest b-waves with the isoflurane group showing slightly shorter implicit times at the higher flash intensities. Oscillatory potentials revealed an early peak in the isoflurane group compared with ketamine/xylazine and urethane groups. Pancuronium did not affect the a- and b-wave, but did increase oscillatory potential amplitudes. Compared with the other anesthetics tested here, ketamine/xylazine + pancuronium was the best combination to minimize eye movement and maximize retinal function. These findings should set the stage for further development and application of high-resolution functional imaging techniques, such as MRI, to study retinal anatomy, physiology, and function in anesthetized rats.

Abstract: Low-cost hybrid up-conversion devices with infrared sensitivity to 1.5 μm were obtained by integrating a colloidal PbSe nanocrystal near-infrared sensitizing layer on a green phosphorescent organic light emitting diode. A ZnO nanocrystal hole blocking layer is incorporated in the devices for keeping the device off in the absence of IR excitation. The maximum photon (1.3 μm)-to-photon (0.52 μm) conversion efficiency is 1.3%. The extension (until 1.5 μm) of the near-infrared wavelengths, which can be converted to visible light, may be able to improve night vision.

Abstract: A system mountable in a motor vehicle. The system includes a camera and a processor configured to receive image data from the camera. The camera includes a rolling shutter configured to capture the image data during a frame period and to scan and to read the image data into multiple image frames. A near infra-red illuminator may be configured to provide a near infra-red illumination cone in the field of view of the camera. The near infrared illumination oscillates with an illumination period. A synchronization mechanism may be configured to synchronize the illumination period to the frame period of the rolling shutter. The frame period may be selected so that the synchronization mechanism provides a spatial profile of the near infra-red illumination cone which may be substantially aligned vertically to a specific region, e.g. near the center of the image frame.

Abstract: Purpose Retinopathy of prematurity (ROP) is a major cause of visual handicap in the pediatric population. To date, this disorder is thought to stem from deficient retinal vascularization. Intriguingly, functional electrophysiological studies in patients with mild or moderate ROP and in the oxygen-induced retinopathy (OIR) model in rats reveal central photoreceptor disruption that overlies modest retinal vessel loss; a paucity of retinal vasculature occurs predominantly at the periphery. Given that choroidal circulation is the major source of oxygen and nutrients to the photoreceptors, the authors set out to investigate whether the choroidal vasculature system may be affected in OIR. Methods Rat models of OIR treating newborn animals with 80% or 50/10% alternated oxygen level for the first two postnatal weeks were used to mimic ROP in humans. Immunohistology staining and vascular corrosion casts were used to investigate the vessel layout of the eye. To investigate the effect of 15-deoxy-Δ12,14-PGJ(2) (15d-PGJ(2); a nonenzymatic product of prostaglandin D(2)) on endothelial cells, in vitro cell culture and ex vivo choroid explants were employed and intravitreal injections were performed in animals. Results The authors herein demonstrate that deficient vascularity occurs not only in the retinal plexus but also in the choroid. This sustained, marked choroidal degeneration is specifically confined to central regions of the retina that present persistent photoreceptor loss and corresponding functional deficits. Moreover, the authors show that 15d-PGJ(2) is a prominent contributor to this choroidal decay. Conclusions The authors demonstrate for the first time pronounced, sustained choroidal vascular involution during the development of ROP. Findings also suggest that effective therapeutic strategies to counter ROP should consider choroidal preservation.

Abstract: PURPOSE. To describe in detail the characteristic clinical phenotype and electrophysiological features of Severe Early Childhood Onset Retinal Dystrophy (SECORD) caused by mutation of RPE65. METHODS. Ophthalmological examination, color fundus photography, visual field testing, detailed electrophysiological assessment, and screening of RPE65 were undertaken in five subjects. Selected patients also had spectral domain optical coherence tomography. RESULTS. All five patients had life-long, extremely poor night vision. Variable degrees of nystagmus were present; three cases lacked nystagmus at the time of assessment. Bilateral disc drusen were evident in three subjects. While case 1 had an undetectable electroretinogram and features supporting a diagnosis of Leber congential amaurosis (LCA) as an infant, her level of acuity and function into the second decade of life was more consistent with SECORD. In two cases, both vision and electrophysiological responses were seen to improve into the second decade of life. The objective demonstration of improved retinal function over time, with electrophysiological testing, has not been previously reported. Cases 4 and 5 had evidence of fine white retinal dots. The authors propose that these represent abnormal accumulations of retinyl esters, as has been demonstrated in animal models, and has also been observed as lipid droplets within the retinal pigment epithelium (RPE). These white dots were seen to fade with time in the patients and were replaced by RPE changes. CONCLUSIONS. The identification of patients with mutations in RPE65 has attained greater significance now that gene replacement trials have begun. The features presented in this article assist in the recognition of this form of LCA/SECORD. (Invest Ophthalmol Vis Sci. 2011;52:292‐302) DOI:10.1167/iovs.106106

Abstract: True color images are produced by combining data collected from one or more color cameras with data collected from one or more infrared cameras. The produced images are the result of combining portions of the visible light data with portions of the infrared light data that may have been captured at dark, at daytime or at low light level conditions. These images appear as normal color images, with infrared information highlighted in a non-distracting fashion. The true color images that are produced in this fashion can also facilitate identification and reproduction of various objects that may not be visible or readily identifiable in infrared or false color imagery.

Abstract: An array camera may be formed from an array of lenses, an array of corresponding apertures, and an array of corresponding image sensors. The array of apertures may be configured so that some image sensors receive light through apertures of different size than other image sensors. Providing apertures of smaller size increases the F/# of an array camera and increases the depth-of-field in a captured image. The array of image sensors may include a near-infrared image sensor. Providing an image sensor array with a near-infrared image sensor may enhance depth information in captured images or increase night vision capabilities of an array camera. Combining an array of image sensors that includes a near-infrared sensor with an array of apertures having different aperture diameters may allow increased depth-of-field imaging, enhanced extraction of depth information from an image, improved night vision, enhanced image clarity or other improvements.

Abstract: Conference Name:2011 International Workshop on Multi-Platform/Multi-Sensor Remote Sensing and Mapping, M2RSM 2011. Conference Address: Xiamen, China. Time:January 10, 2011 - January 12, 2011.

Abstract: Leber congenital amaurosis (LCA) is a severe congenital or early-onset inherited retinal dystrophy that classically presents with searching nystagmus, absence of normal pupil responses, flat electroretinograms (ERGs), minimal, if any, vision beyond infancy, and an initially normal fundus appearance, followed by the development of pigmentary changes over time. The term LCA has traditionally been used when these features present within the first 6 months of life, whereas a variety of terms such as juvenile retinitis pigmentosa,1 early childhood onset retinitis pigmentosa,2 or severe early childhood onset retinal dystrophy (SECORD)3 have been used to describe milder forms of the disease that present after 1 year. LCA and SECORD are genetically extremely heterogeneous, and are caused by >16 genes (AIPL1, CEP290, CRX, CRB1, GUCY2D, IMPDH1, IQCB1, LCA5, LRAT, MERTK, RD3, RDH12, RPGRIP1, RPE65, SPATA7, and TULP1). All except CRX and IMPDH1 exhibit autosomal recessive inheritance in which some de novo mutations result in an autosomal dominant trait.3–5 The gene AIPL1 encodes aryl hydrocarbon receptor interacting protein-like 1 (AIPL1), a 384-amino acid protein with three tetratricopeptide repeat motifs. AIPL1 has been suggested to play a role in photoreceptor development6 and protein farnesylation7 and as a chaperone for NUB1, Hsp70, Hsp90, and photoreceptor-specific phosphodiesterases (PDE6β).8–12 Although AIPL1 was initially thought to be expressed only in adult rod photoreceptors,13 its expression in adult rodent cones has now been demonstrated.14 Mutations in AIPL1 are estimated to account for approximately 5% to 10% of all cases of LCA.4,15 Patients usually have severe vision loss (ranging from 20/200 to LP), but milder forms that would fit the definition of a later onset rod-cone dystrophy have also been reported.2,16–19 Other typical features include poorly responsive pupils, nystagmus, hyperopia, and unrecordable ERGs. The fundus appearance in patients with AIPL1 mutations can appear normal early in the disease, but most patients eventually demonstrate a pigmentary retinopathy with a high prevalence of macular atrophy. One series demonstrated that cataracts and keratoconus were common in those with homozygous AIPL1 mutations.18 Spectral domain-optical coherence tomography (SD-OCT) has shown severe loss of outer retinal thickness in the macula, lamellar disorganization, and increased inner retinal thickness.16 Successful gene replacement therapy in AIPL1-deficient mouse models has raised the hope that such methods could be translated for human treatment.20,21 However, Jacobson et al.16 recently studied the feasibility of treatment in a series of patients with AIPL1 mutations and concluded that the severe photoreceptor degeneration seen might mean they were not good candidates for gene replacement therapy unless and that evidence would be needed in much younger patients of some photoreceptor preservation. We herein report three young patients with mutations in AIPL1 who presented with the clinical features of LCA but had residual electroretinograms characterized by slow insensitive scotopic responses and absent photopic responses. The presence of these residual ERG responses potentially indicated greater photoreceptor preservation than seen in older patients and suggested that these patients might be better candidates for gene replacement therapy than previously considered.

Abstract: The present application provides a robust, illumination invariant apparatus and method for detecting and recognizing various traffic signs. A robust method for detecting and recognizing the traffic signs using images captured by a digital color and night vision camera, the said method characterized in being illumination invariant comprising the processor implemented steps of: transforming RGB image into HSV color model and subsequently extracting desired color components by using color quantization; filtering the noise components in the HSV color model based on object symmetrical shape property; detecting edges of the objects and subsequently detecting the distinct objects in the noise components filtered image; classifying the shapes of the traffic signs based on sha pe of the determined distinct objects; and recognizing the classified shapes of the traffic signs by template matching. Further, the method provides the provision for warning the driver by use of the recognized data of the traffic signs.

Abstract: The lighting of residential streets and public spaces is crucial to public safety of pedestrians after dark. One important objective of safety needs is facial recognition at a distance. The authors state that studies in the past have not truly measured illumination required for facial recognition due to the methodology used to conduct them. The authors suggest improved methodology that would more reliably measure the ability to recognize a target's facial expression, as well as gender, age and race, from a distance, in order to make more informed decisions about personal safety. The authors hope that this new approach will lead to a better understanding of how lighting could be used to enhance safety on the streets.

Abstract: Non-technical summary When rod and cone photoreceptors in the eye respond to light, they need to recover, and the first step in recovery involves a protein called G-protein receptor kinase (GRK). Rods, which underlie night vision, employ a variant called GRK1, whereas cones, which mediate day vision, typically employ a variant called GRK7. We have engineered rod cells in the zebrafish retina that additionally express the cone variant, GRK7. By recording electrically from these modified rods, we have found that they are less sensitive to light than normal rods, in that regard mimicking cones. We have also found evidence to suggest that the size of the cell's response to a single photon (the smallest particle of light) is normal when recovery is mediated by GRK1, but is small (and hence somewhat cone-like) when mediated by GRK7. These results help us understand the differences between rod and cone photoreceptors.

Abstract: We have compared the time course of dark adaptation of the human scotopic visual system, measured psychophysically and from the b-wave of the electroretinogram (ERG), for bleaches ranging from a few percent to near total. We also measured light adaptation, in order to apply a "Crawford transformation" to convert the raw measurements of dark adaptation into equivalent background intensities. For both the "psychophysical threshold equivalent" intensity and the "ERG b-wave sensitivity equivalent" intensity, the equivalent background declined over much of its range with an "S2" component, though with somewhat different slopes of -0.36 (psychophysical) and -0.22 (ERG) log(10) unit min(-1), respectively. In addition, the magnitude of the equivalent background was approximately 1 log(10) unit lower in the psychophysical experiments than in the ERG experiments. Despite these differences, the two approaches extract a common time course for the decline in level of free opsin following moderately large bleaches. We conclude that the recovery of psychophysical scotopic visual threshold over the S2 region reflects events that are present by the stage of the first synapse of rod vision, stemming ultimately from the presence of unregenerated opsin in the rod outer segments.

Abstract: To evaluate night vision disturbance and investigate correlations between pre- and post-treatment parameters and glare scores in orthokeratology patients. Twenty-eight right eyes of 28 patients were enrolled in this study. Corneal topography and a night vision test (NVT) to evaluate the extent of glare were performed after orthokeratology. From the corneal topography, two indices [surface regularity index (SRI) and surface asymmetry index (SAI)] were calculated. Fourier analysis was performed on the topographic data from the central 6 mm, and data were decomposed into asymmetric and higher order components for analysis. There was no correlation between the glare score and pre-treatment keratometric value, pre-treatment cylinder, post-treatment sphere, and post-treatment cylinder. However, there was a statistically significant correlation between pre-treatment sphere and glare score (Pearson correlation coefficient, r = −0.54, p < 0.01). SRI and SAI significantly correlated with glare score (SRI: r = 0.52, p < 0.01, SAI: r = 0.41, p < 0.05). Higher order and asymmetric components were also significantly correlated with glare score (asymmetry: r = 0.61, p < 0.01, higher order: r = 0.67, p < 0.001). The glare score was significantly correlated with corneal irregularity, and appeared to be a beneficial parameter for assessment of night vision performance in patients receiving orthokeratology.

Abstract: We present the design and first field trial results of an all-day all-weather enhanced and synthetic-fused multi-band colour night vision surveillance and observation system. The system augments a fused and dynamic three-band natural-colour night vision image with synthetic 3D imagery in real-time. The night vision sensor suite consists of three cameras, sensitive in, respectively, the visual (400–700 nm), the near-infrared (NIR, 700–1000 nm) and the long-wave infrared (LWIR, 8–14 mm) bands of the electromagnetic spectrum. The optical axes of the three cameras are aligned. Image quality of the fused sensor signals is enhanced in real-time through dynamic noise reduction, super resolution and local adaptive contrast enhancement. The quality of the LWIR image is enhanced through scene-based non-uniformity correction. The visual and NIR signals are used to represent the fused multi-band night vision image in natural daytime colours, using the Colour-the-Night colour remapping technique. Colour remapping can also be deployed to enhance the visibility of thermal targets that are camouflaged in the visual and NIR range of the spectrum. The dynamic false-colour night-time images are augmented with corresponding synthetic 3D scene views, generated in real-time using a geometric 3D scene model in combination with position and orientation information supplied by the Global Positioning System and inertial sensors of the system. Initial field trials show that this system provides enhanced situational information in various low-visibility conditions.

Abstract: The invention provides a colorized night vision image brightness enhancement method applicable to an automotive assisted driving system The method comprises the following steps of: firstly, transforming a night vision colorized image from a red, green and blue (RGB) space to a luma and chroma (YUV) space to overcome the shortcoming of color distortion caused by direct processing of the night vision colorized image in the RGB space; then processing a brightness component image by using an S-curve correction Retinex algorithm so as to enhance the detail and the brightness of the image; enhancing the brightness component image by a selective nonlinear grey level mapping method and keeping good shadow information; and finally, performing weighed fusion on the two enhanced images by a weighed fusion method and inversely transforming the weighed fusion brightness component image and a UV component image to the RGB space for displaying The enhanced image acquired by the method keeps the necessary shadow information and has the detail and the brightness applicable to vision observation; and the night vision colorized image has a good enhancement effect

Abstract: Simulation can be defined as malingering, or sometimes functional visual loss (FVL). It manifests as either simulating an ophthalmic disease (positive simulation), or denial of ophthalmic disease (negative simulation). Conscious behavior and compensation or indemnity claims are prominent features of simulation. Since some authors suggest that this is a manifestation of underlying psychopathology, even conversion is included in this context. In today's world, every ophthalmologist can face with simulation of ophthalmic disease or disorder. In case of simulation suspect, the physician's responsibility is to prove the simulation considering the disease/disorder first, and simulation as an exclusion. In simulation examinations, the physician should be firm and smart to select appropriate test(s) to convince not only the subject, but also the judge in case of indemnity or compensation trials. Almost all ophthalmic sensory and motor functions including visual acuity, visual field, color vision and night vision can be the subject of simulation. Examiner must be skillful in selecting the most appropriate test. Apart from those in the literature, we included all kinds of simulation in ophthalmology. In addition, simulation examination techniques, such as, use of OCT (optical coherence tomography), frequency doubling perimetry (FDP), and modified polarization tests were also included. In this review, we made a thorough literature search, and added our experiences to give the readers up-to-date information on malingering or simulation in ophthalmology.

Abstract: Image fusion is an important component of many applications such as inspection, night vision, medical diagnosis, and electro-optical (multispectral) targeting. In this paper, we build upon our previous results for image fusion metrics by applying the methods to satellite imagery versus night vision (visual and infrared imagery) and single-metric biomedical image fusion analysis. Multispectral examples include satellite imagery for land-cover analysis. In this paper, we explore a variety of metrics that have been used to quantify the performance of the fused image products. The exhaustive conclusive analysis over all possibilities is not realizable, so in this paper we group the various metrics into categories and demonstrate an application of the metrics to satellite LANDSAT imagery using an entropy-based image fusion method. From the many metrics analyzed, we found the Image Structural Similarity Based (ISSB) metrics are most useful.

Abstract: Systems and methods for interweaving infrared and visible moving image data using a single optical system and imager device based on an infrared input signal and a visible input signal are disclosed. Infrared image frames can be substituted in for complete visible image input frames or for partial visible image input frames, i.e. substituting in an infrared image input frame for one or more of the color channels in one or more visible image input frames. Moving video or computer-generated moving graphics can include both infrared and visible image data to be displayed users viewing the resulting images with and without night vision imaging devices. In particular, the system and method can be used in projection systems for night-vision imaging device team training simulators to reduce the cost of the system while increasing the ease of use and performance of such systems.

Abstract: A headpiece assembly for use with a night vision mounting arm includes a bump shell and an interior suspension assembly for seating on the head of a human. A mounting bracket is secured to the front of the bump shell for removably attaching the night vision mounting arm to the bump shell. A ballistic shell has a bottom forming an opening and a coupling mechanism for removably securing the ballistic shell to the bump shell when the ballistic shell is placed over the bump shell. The ballistic shell has a front and a notch extending upwardly from the opening into the front for receiving the mounting bracket when the ballistic shell is placed over the bump shell so as to permit the night vision mounting arm to be attached to the bump shell during use of the ballistic shell.

Abstract: A pixel design is disclosed. The pixel includes a photo-sensitive element. A first reflective layer substantially overlies the photo-sensitive element. A second reflective layer substantially underlies the photo-sensitive element and forms a cavity with the first reflective layer that is non-resonant with respect to photon absorption. An aperture is formed in either the first reflective layer or the second reflective layer. When electromagnetic radiation enters the aperture, the first reflective layer and the second reflective layer are configured to reflect the electromagnetic radiation substantially toward each other until substantially absorbed in the cavity.

Abstract: The thermal analysis (TA) of the wave propagation in the long-wave (LWIR) infrared bands, performed on metamaterials and nano-materials, is suitable for manufacturing a new type of infrared (IR) thermal vision camouflage, useful for defence, military and security application and to evaluate the capability of new kind of materials to block night vision (NV) thermal sighting capabilities as new countermeasure technology. This is mainly generated by the very detailed signature characterization database, available in most automatic vision systems that are able to detect targets by the IR spectral signature provided by the IR sensor. These metamaterials, called photonics band gap devices (PBG) or more in general photonic crystal (PhC), works on IR photons providing absorbing, transmission and reflecting bands. All the optical properties are function of the specific nano design tuned in the thermal wavelength.

Abstract: To determine if the L-type calcium channel participates in the generation of the light-rise of the electro-oculogram (EOG) in man. The aim was to use nifedipine, a specific, L-type calcium channel inhibitor and determine the effects on the light-rise of the EOG in healthy participants. The EOG was recorded in 14 participants before and after a 10 mg oral dose of fast-acting nifedipine. The Arden index, time to peak of the EOGs and pulse were recorded before and after ingestion of nifedipine. The test–retest variability of the EOG’s light-rise in the absence of nifedipine was performed on 11 of the participants. The mean ± SEM oral dose was 147 ± 9 μg/kg. Scotopic electroretinograms (ERGs) were recorded at four intensities (0.0067, 0.0849, 0.364 and 1.140 cd.s.m-2) in six participants before and after a 10 mg oral dose of nifedipine. The light-rise of the EOG was significantly reduced in five participants by −22.80 ± 5.6% (p = 0.021), whilst in four of the participants the light-rise increased by +15.7 ± 1.9% (p = 0.033). The results of the test–retest EOGs showed a range of −9.1 to +9.8% Arden index in the absence of nifedipine. Thus, the responses of five participants were not included in the analysis, as the change in the EOG with nifedipine was within this range. The differences in the time to peak of the light-rise were not significantly different in those that showed an increase (p = 0.33) or a decrease (p = 0.87) in the EOG after nifedipine. Pulse rate was not significantly different after nifedipine in the group that showed an increased light-rise (p = 0.77) or in those whose light-rise fell after nifedipine (p = 0.33). No significant effect was observed on the a- and b-wave amplitudes and implicit times for the scotopic components of the scotopic ERG. The L-type calcium channel contributes to the light-rise of the EOG in man.

Abstract: Uncooled Infrared (IR) focal plane arrays are an enabling technology for both military and commercial high sensitivity night vision cameras. IR imaging is accomplished using MEMS microbolometers fabricated on read-out integrated circuits and depends critically on the material used to absorb the incoming IR radiation. Suitable detector materials must exhibit a large temperature coefficient of resistance (TCR) and low noise characteristics to efficiently detect IR photons while also maintaining compatibility with standard integrated circuit (IC) processing. The most commonly used material in uncooled infrared imaging detectors is vanadium oxide deposited by reactive ion beam sputtering. Here we present a comparison of vanadium oxide thin films grown via commercial reactive ion beam sputtering to films grown using reactive pulsed DC magnetron sputtering. Films deposited using both methods were optically and structurally characterized using Raman spectroscopy, transmission electron microscopy, atomic force microscopy and grazing incidence X-ray diffraction. The measured electrical properties of the films were found to be very sensitive to the deposition conditions used. The ion beam sputtered films contained twinned FCC VOx nanocrystals with sub-nanometer twin spacing, in the form of large 10-20 nm wide columnar/conical grains. In contrast, the un-biased magnetron sputtered films consisted of equiax grains of FCC VOx (5-10 nm) encapsulated in an amorphous matrix. However, applying an RF bias to the sample substrate during the magnetron sputtering process, resulted in films that are similar in structure to ion beam deposited VOx. These differences in microstructure and composition were then correlated to the measured resistivities and TCRs of the films.